I've been looking for a G4 iMac for a long long time now, but they are usually pick up only and/or go for stupid prices. I've missed out on a few good ones over the past two years by not watching the end of an auction.
Anyhoo, I saw a non working iMac with the 17" screen and the 1.25GHz processor locally, and it passed in. I offered $20, which they accepted. I picked it up tonight, and it would turn on but nothing on the screen. I realised that I needed to plug in some headphones to hear if any sounds played, and of course there were 3 chimes when turned on. RAM!
So I took the base off, cleaned it all thoroughly, and swapped the 256MB chip for a 512MB I had spare. Put it all back together again, and POW! Screen is crisp and bright, it booted quickly to Mac OS X 10.3.9, and runs nice and quietly. Huzzah, success!
Only thing to do now is give it a nice clean and detail on the exterior, and figure out why one RAM chip is not showing up. I never knew there were two different types of RAM in these things, but one of them is not recognising the chip. I should technically have 1GB from two 512MB chips...